The present invention concerns a parcel tying-up machine, which is to be placed between an input conveyor belt for the parcels to be tied up and an output conveyor belt for the tied-up parcels, with a frame and with a tying-up unit, which has a guide apparatus for placing the tie round a parcel, and a tie-joiner, which is placed under the conveyor path in the tying-up plane and is designed for joining together the loop ends of the tie.
Tying-up machines on these lines are known and are used more specially for tying up parcels of newspapers or periodicals, although they may be used for other parcels, tied up with synthetic a resin tape, cord or wire. If synthetic resin tape is used for tying up, the tie-joiner will be a welder, with whose help the ends of the loop placed round the parcel are welded together. On the other hand, if a cord is used for tying up, the tie-joiner will be a knotter for knotting together the ends of the loop placed round the parcel. If a wire is used for tying up, the tie-joiner may be a twisting unit with which the ends of the wire loop, threaded round the parcel, are twisted up together. If, on the other hand, a steel strap or band is used for tying up, the tie-joiner wil be a swaging unit with which the ends of the steel strap loop, placed round the parcel, are joined together by plastically bending them and possibly using a sheet metal sleeve.
In the case of parcel tying-up machines to date, the parcels, which are moved to the machine by a conveyor belt, have to be stopped, put into the tying-up position and after tying-up have to be pushed on to an output conveyor belt. Because of the braking of the parcels, tying them up and then starting them moving again, the transport of the parcels from one part of the apparatus to another is slowed down to a large degree, that is to say the conveyor belt may only be worked at a given rate of so many parcels in each unit of time as dependent on the rate at which the parcels may be tied up by the typing-up machine. For this reason, the spacing between the parcels on the input conveyor belt has to be generally large in size.